In 2005, Deane Baldwin, operations director and PACS administrator at Mercy Medical Center, Des Moines, Iowa, and colleague Roger Wilson, Mercy’s systems and networking manager, were facing two PACS-related challenges: They were using version 4.0 of the Kodak Carestream PACS from Carestream Health, Rochester, NY, and needed to upgrade to version 5. They also had a business continuity problem that needed solving fast.
“Our plan at that time was waiting for the next set of hardware to come off the assembly line and be restored by tape,” said Wilson. “We extrapolated that we would have been down for weeks trying to recover from a major system outage. So we sat down with our vendors and said, ‘We’ve got to come up with something better.’ ”
Those vendors included Kodak’s Health Group—now Carestream—as well as Cisco and IBM. “We said, ‘OK, we’ve got this data facility and our main campus site, and we have dark fiber between the two,’ ” recalled Wilson. “What can we do with all of this to do the upgrade and fix our business continuity issue? PACS is very critical to our patients. Being able to bring the system back up within hours after a disaster would be critical to us providing quality patient care. It took several meetings with all the vendors to come up with a solution. There were many iterations of the drawing.”
That was the genesis of Mercy’s current PACS environment, a clustered PACS with an expanded SAN. The new platform, which includes all three original vendors, not only gives the hospital fully featured data archiving and storage, but also allows Mercy to offer that service to affiliated hospitals in rural Iowa. “We have a lot of networked affiliate hospitals that are just starting to become interested in technologies like PACS and CR,” explained Baldwin. So far, Mercy has installed satellite workflow managers for three affiliate hospitals, and it expects to bring on more rural hospitals over the next 2 years.
“Their decision to make this investment is going to lead to a lot of positive things,” predicted Mitch Goldburgh, senior vice president of business development and marketing at InSite One Inc, Wallingford, Conn, who acted as a consultant as Mercy transitioned to its clustered PACS environment. “It’s clearly a long-term investment.” Goldburgh notes that while the multisite storage model is far from the norm, other medical facilities around the country, including the Cleveland Clinic, have adopted similar platforms.
Of course, it’s not easy—or inexpensive—to set up this kind of environment. Baldwin and Wilson secured the budget in part because their model established a disaster recovery road map for multiple systems within the hospital’s IT infrastructure. “In the event of a network failure, not only does the clustered PACS system allow us to essentially not have downtime,” said Baldwin, “but in construction of that new SAN fabric, the whole hospital really benefited.”
Because the SAN fabric Mercy was operating on in 2005 wasn’t scalable, Baldwin and Wilson sat down with their vendor, Cisco Systems Inc, San Jose, Calif, to work out the details of a forklift upgrade. “At the heart of our new SAN is a pair of fiber switches,” said Wilson. “We have a pair of IBM DS6800 storage units, one at our main data center and one at our capitol location, and synchronous Metro Mirroring keeps the data complete between the two. The data isn’t passed back until it’s been updated on both IBM storage systems. We also added a DS4800 to our archive. At the secondary facility, we have a 3584 tape robot and tape drives. So when the modalities send the images to PACS, they get written to tape, to the long-term and the high-speed.”
Now, the elapsed time be-tween when an image first hits the PACS server to when a fourth copy is written to tape is under 20 minutes. “It’s written to both 6800s and the 4800 in a couple of minutes,” said Baldwin. “Depending on the business on the server at the time, it may be as many as 15 minutes before we get our fourth copy.”
Different rules are applied to different types of studies for storage. After that, they are routed to the enterprise information management system. “There can be different storage plans for pediatrics, for mammography,” noted Baldwin. “And you can change the rules retroactively. The Carestream software allows you to purge studies that don’t need to be stored anymore. And you can write a copy to tape, if you need to, which allows you to manage your disk space more efficiently.”
Planning for Pitfalls
There are disadvantages to using a mirroring model that have to be considered—the most obvious of which is, should there be an error at one location, replication would recreate the error. Goldburgh explains that one alternative to solve this issue is vaulting, a method employed within InSite One’s storage system.
“Once an image enters the environment, it’s fingerprinted,” he said. “That fingerprint is code that represents this image. Every 90 days, we reread that image, and when we transfer from the customer site to our virtual storage, every node is verified. If there’s a change in the data, then we restore it to its original format. There are also archives out there, the IBM GMAS or the HP archiving service, that use software with self-healing capabilities, so if a node goes bad, it knows to go get the data elsewhere and be restored.”
Then prediction of storage becomes an issue. Goldburgh notes that CT exam sizes from one device within a single institution can vary by as much as 33%. If a site within a multisite infrastructure upgrades from 16- to 32-slice CT, that dramatically changes its storage needs. “How do you share data and store it for the long term?” said Goldburgh. “The clinical life of the data exceeds the life of the technology used to store it. So as your volumes are growing because it’s multi-institutional, how are you going to maintain that data?”
Goldburgh cites two principal problems with the multisite storage model: patient identification and retention. “One factor that’s complex is making sure names are spelled the same way at all locations,” he said. “We also see sites where the retention policy is 8 years, and some that say to purge in 5. Now you have data maintenance complexities, because you have to be sure everyone knows how long to save.”
|Mercy Medical was using a Carestream Health PACS system. The vendor teamed up with others to help transition the hospital to a clustered PACS along with an expanded SAN.|
Those same problems can be applied at a more granular level to single institutions, or multiple sites under the same ownership, as well. “How do you share radiology data with cardiology data with mammography data?” said Goldburgh. “There are still institutions where they share CDs between departments, which is like writing a letter to find out what’s for dinner. In a single institution with different departments, or in multiple radiology centers, the first challenge is defining the enterprise.”
Mercy needed a scalable solution: a PACS environment that addressed not only its current storage needs, but the storage needs it would face in years to come. “It’s stunning, how the growth in PACS has exploded over the last few years,” said Wilson, in a plaint familiar to PACS administrators everywhere. “The size of the images being brought in has exploded. It’s more, bigger, much faster. But from an IT standpoint,” he went on, “we began to see return on investment from the first day we went live, because the clustered PACS addressed problems we’d been having in terms of capacity.”
With business continuity down pat and its storage problem worked out, it was time to focus on another aspect of building the business. Mercy turned to its rural affiliates to offer them satellite Carestream PACS systems, which share the database with the main workflow manager at the hospital—offering incredible advantages in terms of continuity of care. “When an image is acquired at one of these rural affiliates, if they have a patient they’re not really sure what to do with, they send that patient to us,” explained Baldwin. “With the ability to transmit these images to the Carestream PACS, they can make a decision about keeping the patient or not.
“A lot of patients in rural communities would much prefer to stay in their community hospital,” he continued. “Also, as far as referring physicians and consultations, the physicians have access to the PACS from home. So the referring provider at the rural affiliate could have a consultation with the radiologist from Des Moines and we can say, you can keep that patient in the facility and treat him there.”
The Cost of Technology
Naturally, there are costs involved with this kind of infrastructure. “Managing the cost of the technology for the life of the data is the challenge,” said Goldburgh. So Mercy is offering storage for the affiliates operating satellite Carestream PACS systems—at a nominal fee. Though the price has yet to be determined, said Baldwin, “we are having those conversations to figure out what it will be. There will be some storage fees, but we anticipate that it will be very cost-effective.”
Goldburgh says the trick to understanding this kind of big-picture plan is realizing there is no material connectivity between services offered and costs being offset. “[Mercy] didn’t set it up as a business center, so they’re not charging a price that would cover all of their costs,” he said. “They’re making their money on referrals. As long as their volumes are increasing, they can say, this might not have been possible without having made this investment.”
Baldwin and Wilson have structured the system in such a way that costs incurred by Mercy for replenishment of disk space and staff time will hopefully be recovered. “It hasn’t been our intention to make money,” said Baldwin.
“We’ve said to the remote facilities, we’ll help you, and we have a PACS support team here at the hospital of about 12 people,” added Wilson. “We’ve offered to help with implementation. And some of the functionality within the Carestream PACS is vendor-neutral. We can do long-term storage from any number of PACS vendors if that remote facility chose to do so. But there are benefits to having the same vendor, so none of them have chosen to do that yet.”
Cat Vasko is a contributing writer for Axis Imaging News. For more information, contact .